Let us imagine the following historical event, one quite typical of Jewish life as it has been practiced worldwide for over two thousand years. On a Sabbath day sometime in the mid-sixteenth century, the Jews of Cochin, a city on the Malabar coast of southwest India, gather in the synagogue for worship. On that day the readings from the Bible include chapters from the book of Exodus and a portion of Chapter 46 from the prophecies of Jeremiah. The first of these readings recalls the slavery of the ancient Israelites in the land of Egypt (thirteenth century B.C.E.); the second announces a divine promise to a different generation (seventh century B.C.E.) that the nation would one day be restored to its ancestral homeland--the land of Israel--from all the far-flung lands of its dispersion. Reflecting on these matters, the rabbi or learned elder tells those assembled chat the history and the hope just read from the Bible are not just words from the past. They are, he says, living words for them: the slavery in Egypt is their own national memory and the promise of national renewal their own collective hope. Hearing this, the congregation nods assent--just as they are doing in a synagogue in Alexandria on that same Sabbath, when Rabbi David ben Solomon ibn Abi Zimra gives his learned address, and just as they are doing in a synagogue in Palestine, after the discourse of the mystic and lawyer Rabbi Joseph Karo.

Thus, though separated east and west and ruled by all the kingdoms of the earth, the Jews the world over were and are one people sharing deep bonds despite external differences of custom and costume. They share similar national memories and hopes rootedin the same biblical texts, which they read yearly and in the same sequence. And they also share a book of common prayers for everyday worship and a fixed pattern of observances for every moment of the calendar year. In this way the teachings and commandments of the Bible, as explained or reformulated by scholars throughout the centuries, have been faithfully preserved and lovingly performed by Jews from Cochin to Kracow and from Bombay to Brooklyn-all to the glory and honor of God.

Judaism is thus the religious expression of the Jewish people from antiquity to the present day as it has tried to form and live a life of holiness before God. It is, on the one hand, an expression of recognizable uniformity, practiced commonly and communally by Jews across the centuries in different lands. But, on the other, it is also a religious expression with great historical variations. Never static, Judaism has changed and challenged its adherents for over two millennia, even as it has been changed and challenged by them in different circumstances and times. This relationship of continuity and change stands at the center of Jewish practice and belief. Since Judaism characteristically understands itself by commenting on its own earlier traditions, let us follow this lead and turn, by way of introduction, to two most instructive texts.

The first of these is a remarkable legend preserved in the Babylonian Talmud, the foremost collection of classical Jewish law and lore (edited in the fifth century C.E., but containing traditions from up to 750 years earlier). In just a few sentences, the narrative discloses the authoritative core of Jewish creative vigor and the very pulse of its unity withindiversity. It shows Judaism to be at once a religion rooted in the Bible--in terms of its beliefs and behaviors, history and hopes--yet radically transformed by the ongoing teachings of the sages. All this is conveyed nn a series of dramatic folk images (not abstract arguments) that extend literary hints found in the Bible itself.

The text has its point of departure in the biblical account of the revelation of the divine Law at Mount Sinai as recorded in the book of Exodus. In the Bible, this is the central moment of ancient Israelite history and religion, for it is the moment, according to tradition, when the ancient Hebrews became a religious nation bound to God. Understandably, then, the divine revelation at Sinai has remained the central religious event for Jews and Judaism ever since. But when we look closely at the biblical text, which apparently only states that the Israelites received the Ten Commandments and a rather limited collection of ordinances at Sinai, we might well wonder how this event, could also be the source of the voluminous laws and practices of historical Judaism.

The biblical passage (in Exodus 19) simply states that, while the nation waited below, "Moses ascended" the mountain to receive God's laws and instructions for them. However, according to Rab, the teacher (third century C.E.) in whose name the legend was transmitted in the Talmud', this textual reference is merely an allusion to a more profound spiritual moment for Moses and the future Jewish people. It is but the merest clue of what "really" took place on that occasion--namely, Moses' spiritual ascension to heaven. There, the legend tells us, the future lawgiver Moses found God adding littlescribal flourishes to the letters of the Law, the Torah. Astonished and perplexed, Moses asked for an explanation. God then told him that a man would arise after many generations, Akiba ben Joseph by name, who would be able to derive "heaps of laws" from each jot and tittle of the Torah. Moses was thus given to understand that the written Law, which he was to receive from God and transmit to the nation, would be adapted to ever new historical situations through creative interpretations of even the smallest of its letters and calligraphic ornaments.